Method and Apparatus for Reliably Delivering Multicast Data

1. A method for reliable delivery of multicast data by a media gateway employing application layer multicast to unicast conversion, said method comprising: establishing a session with a receiver; mapping a multicast connection to a unicast resource identifier; transmitting to the receiver, information regarding available programs from a server, said available programs comprising a plurality of multicast addressed data packets, wherein said information has been modified by removing multicast connection information from at least one of said available programs; receiving a request from said receiver to receive one of said available programs, said request including a receiver port address; joining, by said media gateway, a multicast group in order to request said one of said available programs from said server as a proxy for said receiver, said receiver having no knowledge of multicast; allocating server ports; receiving multicast addressed data packets from an external network; converting said multicast addressed data packets to unicast addressed data packets, said conversion being performed above a transport layer of a communications protocol; and transmitting said converted data packets to said receiver port address.

2. The method according to claim 1 , further comprising: transmitting a response to said received request to said receiver.

3. The method according to claim 1 , further comprising: receiving, from an external network, an announcement containing information regarding said available programs, said available programs comprising a plurality of said multicast addressed data packets; storing said information; modifying said information; and transmitting a response to said request to receive one of said available programs, said response including a server port address.

4. The method according to claim 3 , wherein said modifying step further comprises removing multicast connection information from said one of said available programs.

5. The method according to claim 3 , further comprising: receiving a request to cease receiving said one of said available programs; releasing resources associated with receiving said one of said available program; responding to said request to cease receiving said one of said available programs; and transmitting an internet group management protocol message if no other requests for said one of said available programs is outstanding.

6. The method according to claim 1 , further comprising: transmitting, via an external interface, an unsolicited internet group management protocol report; receiving, via said external interface, an internet group management protocol query; and transmitting, via said external interface, an internet group management protocol query response.

7. A media gateway for reliable delivery of multicast data employing application layer multicast to unicast conversion, comprising: means for establishing a session with a receiver; means for mapping a multicast connection to a unicast resource identifier; means for transmitting to the receiver, information regarding available programs from a server, said available programs comprising a plurality of multicast addressed data packets, wherein said information has been modified by removing multicast connection information from at least one of said available programs; means for receiving a request, from a receiver, to receive one of said available programs, said request including a receiver port address; means for joining, by said media gateway, a multicast group in order to request said one of said available programs from said server as a proxy for said receiver, said receiver having no knowledge of multicast; means for allocating server ports; means for requesting said one of said available programs from said server as a proxy for said receiver, said receiver having no knowledge of multicast; means for receiving said multicast addressed data packets from an external network; means for converting said multicast addressed data packets to unicast data packets, said conversion being performed above a transport layer of a communications protocol; and means for transmitting said converted data packets to said receiver port address.

8. The apparatus media gateway according to claim 7 , further comprising: means for transmitting a response to said received request to said receiver.

9. The media gateway according to claim 7 , further comprising: means for receiving, from the external network, an announcement containing information regarding said available programs, said available programs comprising a plurality of said multicast addressed data packets; means for storing said information; means for modifying said information; and means for transmitting a response to said request to receive one of said available programs, said response including a server port address.

10. The media gateway according to claim 9 , wherein a communications protocol is used between the apparatus, which is a media gateway, and said receiver to establish a multicast-to-unicast mapping and to deliver said converted data packets to said receiver, further wherein said communications protocol being a real-time streaming protocol.

11. The media gateway according to claim 9 , wherein said means for modifying further comprises means for removing multicast connection information from said one of said available programs.

12. The media gateway according to claim 11 , further comprising: means for receiving a request to cease receiving said one of said available programs; means for releasing resources associated with receiving said one of said available program; means for responding to said request to cease receiving said one of said available programs; and means for transmitting an internet group management protocol message if no other requests for said one of said available programs is outstanding.

13. The media gateway according to claim 7 , further comprising: means for transmitting, via an external network, an unsolicited internet group management protocol report; means for receiving, via said external network, an internet group management protocol query; and means for transmitting, via said external network, an internet group management protocol query response.